Introduction to Organic Chemistry

Introduction to Organic Chemistry

• Organic substances are created by plants or animals; they can be natural or synthetic.
• Inorganic substances come from soil; they can be natural or synthetic.
• Organic chemistry emerged as a science field in the early 1800s, pioneered by Jon Jacob Berzelius.
• Chemical compounds are classified as organic (from plants/animals; natural or synthetic) or inorganic (from minerals/non-living matter; natural or synthetic).
• The need for developing synthetic rubber during World War II accelerated the advancement of organic chemistry.

Organic Compounds in Daily Life and Industries

• Organic compounds are prevalent in everyday life (sugar, fats, vinegar, perfumes, paints, medicine).
• The production and use of organic compounds have greatly improved various industries, including plastics, medicine, paints, and pesticides.
• Disadvantages of organic chemistry involve the production of toxic gases and substances during processing, potentially hazardous materials (like alcohols and benzene), and the pollution risk posed by some organic compounds (pesticides).

Difference between Organic and Inorganic Compounds

• Inorganic compounds lack carbon and hydrogen. Examples include iron (Fe), inorganic salts (like NaCl), and limestone (CaCO3).
• Organic compounds contain carbon and hydrogen, with carbon forming the fundamental backbone of their structure. Examples include ethanol (CH3CH2OH), acetic acid (CH3COOH), and acetone (CH3COCH3).

Importance of Carbon

• Carbon exists naturally as graphite and diamond.
• Carbon's atomic number is 6, mass number is 12, and it possesses 4 valence electrons.
• Carbon's ability to form 4 covalent bonds, single, double, and triple bonds, and cyclic and acyclic compounds is key in its importance in organic chemistry.
• Carbon-hydrogen bond strength is comparable to carbon-carbon bond strength.

Classification of Organic Compounds

• Organic compounds are broadly categorized as hydrocarbons and derivatives of hydrocarbons.
• Hydrocarbons are further subdivided into acyclic (open chain) and cyclic (closed chain) compounds, also classified as aliphatic or aromatic, and saturated or unsaturated.
• Derivatives include compounds with functional groups like alcohols, ethers, carbonyl compounds (acids, acyl halides, anhydrides, aldehydes, ketones, esters), amines, amides, alkyl halides, and organometallic compounds.

First Derivatives of Hydrocarbons: Acids

• Acids have a carboxyl functional group (-COOH).
• Examples include formic acid, acetic acid, lactic acid, citric acid, oxalic acid, and malic acid.
• Acids are crucial to food processing.

Alcohols

• Alcohols have a hydroxyl functional group (-OH).
• Examples include ethyl alcohol (ethanol) and methyl alcohol (methanol).
• They are derived from the fermentation of fruits or wood/agricultural sources and used in various fields (drinks and other industrial processes).

Aldehydes

• Aldehydes have an aldehyde functional group (-CHO).
• Examples include vanillin, benzaldehyde, and cinnamaldehyde.
• They impart flavor and odor characteristics.

Ketones

• Ketones have a carbonyl functional group (-CO-) within the carbon chain.
• Acetone (CH3COCH3) is the common example and used as a solvent.

Esters

• Esters have an ester functional group (-COO-).
• They often have fruity aromas and are widely used in food.

Alkyl Halides

• Alkyl halides have a halogen functional group (X) attached to an alkyl group.
• Examples include chloroform (CHCl3) and carbon tetrachloride (CCl4).
• They have diverse applications like as solvents and refrigerants.

Naming Hydrocarbons

• The naming of hydrocarbons follows IUPAC (International Union of Pure and Applied Chemistry) nomenclature.
• Prefixes indicate the number of carbon atoms in the chain.
• Suffixes denote the type of hydrocarbon (alkane, alkene, alkyne).

Saturated, Unsaturated Hydrocarbons

• Alkanes (saturated hydrocarbons) have only single bonds.
• Alkenes (unsaturated hydrocarbons) have at least one double bond.
• Alkynes (unsaturated hydrocarbons) have at least one triple bond.

Third Cycle Hydrocarbons

• Acyclic and homocyclic hydrocarbons are examples of saturated and unsaturated hydrocarbons, including cyclic alkanes, alkenes, and alkynes; and aromatic and non-aromatic compounds.
• Aromatic compounds contain benzene rings; benzenoid rings (aromatic) have a benzene ring.
• Heterocyclic compounds have carbon & other elements (N,S,O).
• Non-benzenoids lack benzene rings.

Aromatic Compounds

• Aromatic compounds meet specific criteria (cyclic structure, alternating double bonds, specific number of π electrons).
• Benzene is the most prominent example.

Bond Cleavage

• Hemolytic cleavage: The bond splits evenly between two atoms (equal electronegativity).
• Heterolytic cleavage: The bond splits unevenly due to differences in electronegativity, creating a cation and an anion.

Reactive Intermediates

• Reactive Intermediates are highly reactive and short-lived species, including radicals, carbocations, and carbanions, taking part in the middle of a reaction in organic chemistry.
• They are crucial in understanding reaction mechanisms.

Organic Reactions (Types)

• Substitution reactions: A substitution reaction takes a sigma bond, breaks it, and replaces an existing one with another at the same atom.
• Elimination reactions: A reaction that breaks two sigma bonds and forms a pi bond.
• Addition reactions: A reaction where to sigma bonds are formed from a pi bond.

This quiz covers the fundamentals of organic chemistry, including the distinction between organic and inorganic substances and their significance in daily life and various industries. It also discusses the historical development of organic chemistry and its applications. Prepare to test your knowledge on these essential concepts!